This invention relates to apparatus and methods for generating data for the measurement of rheological and viscoelastic properties of curing rubber samples.
Rheological and viscoelastic properties of curing rubber samples are known to be important to the uses of rubber from which such samples are taken. Several important properties are known in relation to the testing of curing rubber samples for stress as measured by oscillating disc cure rheometers. Such properties include peak strain; viscous modulus, a rheological property of rubber before the cure reaction begins, and loss modulus, a viscoelastic property of substantially completely cured rubber, both designated G"; elastic modulus, the record of stress values divided by peak strain before the cured reaction begins and known as G'; the storage modulus, equivalent to elastic modulus for substantially completely cured rubber and also designated G'; complex modulus, calculated according to the equation EQU G*=.sqroot.(G').sup.2 +(G").sup.2 ;
dynamic viscosity calculated according to the equation N*=G"/W, where W=frequency of oscillation of stress testing; and tangent .delta., calculated according to the equation tangent .delta.=G"/G'.
Prior to the invention, the generation of data for the measurement of the foregoing and other rheological and viscoelastic properties of curing rubber samples required three different samples to be testd on two different types of machines to obtain similar parameters.